Call set up failure rate metric and communication network optimization based thereon

ABSTRACT

A computer-implemented method includes generating at least one call detail record for each call initiated on a communication network, aggregating the call detail records generated over a predetermined time period to provide an aggregated call detail record, and calculating a call set up failure rate for the calls from the aggregated call detail record, wherein the call set up failure rate is a measure of the amount of calls that failed prior to ringing at a called party&#39;s device. The computer-implemented method further includes adjusting parameters of the communication network when the call set up failure rate is above a threshold.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a continuation of U.S. patent application Ser. No.16/880,558, filed on May 21, 2020, the entire contents of which areexpressly incorporated by reference herein.

TECHNICAL FIELD

Embodiments discussed herein generally relate to methods and systems forproviding a metric for call set up failure rates, and for optimizing acommunication network based on the call set up failure rates.

BACKGROUND

Communications between parties via user devices are invaluable for manypersonal and professional purposes. These communications may includevoice calls and video calls supported by communication networksincluding mobile networks (4G, 5G, etc.), WiFi networks, and theInternet. In voice over long-term evolution (VoLTE) calls, the voicecalls are made over a 4G LTE communication network. In VoLTE, voice datapackets are sent over the Internet, and the voice data packets are givenpriority over other types of data packets to provide high definitionvoice quality. VoLTE also provides faster connection speeds and higherdata transfer rates compared to 2G and 3G networks that use circuitswitched protocols.

In some circumstances, a voice call initiated on a network by a callingparty may fail during call set up on the network before a notification(e.g., a ring) is received by the called party. The calling party mustthen redial to initiate the call again. Such call failures mayinconvenience the network subscribers, and waste network resources.Calls may fail during call set up for various reasons such as networkdelays in call set up signaling and response times as may occur duringtraveling of the calling party or the called party, failure to receive amessage at the originating or terminating side within a predeterminedtime limit, failure to establish a dedicated bearer for the voice call,failures during circuit switched fall back (CSFB) from an LTE network,or issues at the radio access network (RAN). The rate at which a networkexperiences call set up failures may vary by day, region, type of userdevice, device software, and several other factors.

US Patent Application Publication 2016/0029228 describes thetransmission of an error code when a communication session fails duringa pre-establishment phase due to failure to establish a dedicated beareron an access network. In response to the error code, the communicationsession is reinitiated on a second access network. While effective,communication networks may benefit from knowing the rate at which callsinitiated on their networks fail prior to notification or ringing at thecalled party. The rate may provide network engineers and personnel witha measurable handle for optimizing and tuning the network to improvenetwork subscriber experience.

Thus, there is a need for providing a metric for the amount of callsthat fail prior to notification or ringing on a given communicationnetwork. The embodiments of the present disclosure attempt to provide atechnical solution to address these needs.

SUMMARY

Embodiments disclosed herein apply to systems and methods fordetermining a call set up failure rate on a given communication network,triggering an indication or alert on the communication network when thecall set up failure rate is above a threshold, and adjusting oroptimizing parameters of the communication network in response to thealert to reduce the call set up failure rate. In one embodiment, acomputer-implemented method for determining a call set up failure ratefor calls initiated on a long-term evolution (LTE) communication networkis disclosed. The method may include generating at least one call detailrecord for each of the calls initiated on the LTE communication network,aggregating the call detail records generated over a predetermined timeperiod to provide an aggregated call detail record, and calculating thecall set up failure rate from the aggregated call detail record. Themethod may further comprise adjusting one or more parameters of the LTEcommunication network when the call set up failure rate is above athreshold to reduce the call set up failure rate.

In another embodiment, a system including a communication networkconfigured to enable calls on user devices is disclosed. Thecommunication network may at least include a server having a processor,a memory, and a communication circuit. The processor may be physicallyconfigured according to computer-executable instructions for generatinga call detail record for a call set up process for each of the callsinitiated by the user devices on the communication network, aggregatingthe call detail records generated over a predetermined time period toprovide an aggregated call detail record, and calculating from theaggregated call detail record a call set up failure rate for theinitiated calls that failed during the call set up process.Additionally, the processor may be physically configured according tocomputer-executable instructions for communicating an alert to a networkcomputer when the call set up failure rate is above a threshold.

BRIEF DESCRIPTION OF THE DRAWINGS

The disclosure may be better understood by reference to the detaileddescription when considered in connection with the accompanyingdrawings. The components in the figures are not necessarily to scale,emphasis instead being placed upon illustrating the principles of thedisclosure.

FIG. 1 is a schematic representation of a communication network,according to one embodiment.

FIG. 2 is a schematic representation of an exemplary call set up processon the communication network, according to one embodiment.

FIG. 3 is flow chart illustrating a computer-implemented method ofdetermining a call set up failure rate on the communication network, andadjusting parameters of the communication network based on the call setup failure rate, according to one embodiment.

FIG. 4 is a representation of a portion of an exemplary aggregated calldetail record (CDR), according to one embodiment.

FIG. 5 is a schematic representation of components of a server on thecommunication network, according to one embodiment.

DETAILED DESCRIPTION

Referring now to the drawings and with specific reference to FIG. 1, asystem 10 including an exemplary communication network 12 for supportinga call between user devices 14 is shown. The user device 14 may includea smartphone, a tablet, a laptop, a personal computer, or othercommunication device. In one embodiment, the communication network 12may be a 4G long term evolution (LTE) network 16 or a 5G LTE network.The LTE communication network 16 may support voice over LTE (VoLTE)calls and/or video over LTE (ViLTE) calls between user devices 14subscribed or otherwise connected to the network 16. In the VoLTE calls,voice data is sent as prioritized data packets over the Internet toprovide high definition voice quality. In some arrangements, thecommunication network 12 may include other types of networks such ascircuit switched or WiFi networks.

The LTE communication network 16 may include a radio access network(RAN) 18 providing wireless connectivity between user devices 14, and anevolved packet core (EPC) 20 involved in call session set up andauthentication, among other things. The EPC 20 may include a policy andcharging rule function (PCRF) 22 which plays a role in setting up adedicated bearer for the VoLTE call. The EPC 20 may connect to anInternet protocol (IP) multimedia subsystem (IMS) 24 involved indelivering multimedia communications (voice, video, etc.) over IPnetworks. The LTE communication network 16 and the IMS 24 may includemany other components and features not shown and discussed here forclarity purposes.

A user device 14 connects, by way of a radio base station (eNode B) 26of the RAN 18, to the EPC 20 which in turn connects to the IMS 24.Initially, a mobility management entity (MME) 28 authenticates the userdevice 14, and establishes default bearers into the Internet 30 and theIMS 24 once the user device 14 is authenticated. The MME 28 may set upan appropriate serving gateway (SGW) 32 which routes data packets to andfrom one or more packet data networks (PDN) 34 that connect to theInternet 30 and the IMS 24.

With the default bearers established, the user device 14 may registertowards the IMS 24 for the VoLTE call via a session integration protocol(SIP) register request. The register request may be sent to a callsession control function (CSCF) 36 which includes a proxy-CSCF (P-CSCF),an interrogating-CSCR (I-CSCF), and an appropriate session-CSCF(S-CSCF). The CSCF 36 is also involved in passing call invites from theuser device 14 to a server 38 on the IMS 24, allowing the server 38 togenerate a call detail record (CDR) 40 for a call set up process foreach initiated call on the network 16 and calculate call set up failurerates (see further details below). In one embodiment, the server 38 is atelephony application server (TAS) 42.

FIG. 2 shows an exemplary call set up process 50 that occurs when a userdevice 52 of a calling party (originating user device) attempts to calla user device 54 of a called party (terminating user device) via the LTEcommunication network. During the call set up process 50, SIP messagesare communicated between the user devices 52 and 54 via an originatingIMS 56 and LTE communication network 58, and a terminating IMS 60 andLTE communication network 62. As used herein, the originating side 64includes the calling party user device 52, the originating LTEcommunication network 58, and the originating IMS 56. Likewise, theterminating side 66 includes the called party user device 54, theterminating LTE communication network 62, and the terminating IMS 60. Insome embodiments, the terminating side 66 may include another type ofcommunication network, such as a circuit switched communication networkor a WiFi network.

The call set up process 50 may include an attempt stage 68 and apre-alerting stage 70 that occur prior to a notification of an incomingcall (e.g., a sound, a ring, a vibration, etc.) being received at theuser device 54 of the called party. The attempt and pre-alerting stages68 and 70 may involve processes such as negotiation of codecs(code/decoders used in analog/digital conversion), decision of type(s)of media to be exchanged (audio, video, etc.), and establishment ofdedicated bearers 72 and 74 on the originating and terminating sides 64and 66, respectively. The call set up process 50 may further include analerting/ringing stage 76 which includes ringing or other notifyingsignal being received at the called party user device 54, and ananswering stage 78 which includes call answering at the called partyuser device 54. Completion of the answering stage 54 establishes thecall and completes the call set up process 50. With the call set upprocess 50 complete, the user devices 52 and 54 may begin exchangingmedia (voice, audio, etc.) packets as desired during the call. Theindividual messages involved in each stage of the call set up process 50are described more specifically below.

When the calling party user device 52 initiates a call to the calledparty user device 54, the user device 52 sends a SIP ‘Invite’ message 80which informs the terminating side 66 of the incoming call. The ‘Invite’message 80 includes a session description protocol (SDP) offer carryinginformation such as media capabilities, and information for negotiatingbandwidths and codecs. The terminating side 66 may acknowledge the‘Invite’ message by sending a ‘100 Trying’ message 82. Additionally, theterminating side 66 may respond with a ‘183 Session in Progress’ message84 which includes an SDP answer to the SDP offer in the ‘Invite’ message80. The SDP answer may contain codec information to assist theoriginating and terminating sides 64 and 66 in selecting a common codecsupported on both of the sides 64 and 66. During this step, thededicated bearers 72 and 74 may be created with the help of the PCRF 22at both the originating and terminating sides 64 and 66. This mayconclude the attempt stage 68 of the call set up process 50.

In the pre-alerting stage 70, the originating side 64 may send aprovisional acknowledgement (‘PRACK’) message 86 to acknowledge the ‘183Session in Progress’ message 84. The ‘PRACK’ message 86 may also be usedto communicate the final selected codec for the call. The terminatingside 66 may respond to the ‘PRACK’ message with a ‘200 OK’ message 88which accepts the final selected codec offered by the originating side64. Additionally, the originating side 64 may send a SIP ‘Update’message 90 providing an updated SDP offer containing the selected codecand confirming that the local conditions are met at the originating side64. The terminating side 66 may respond with a ‘200 OK Update’ message92 containing information that the conditions are met at the terminatingside 66 too. If any of the above messaging steps of the attempt andpre-alerting stages 68 and 70 are not completed within a predeterminedtime limit measured by a network timer, the call set up process 50 mayfail. Failures may be caused by delays at either of the originating orterminating sides 64 and 66.

In the alerting/ringing stage 76, the terminating user device 54receives a notification (e.g., a ring, a sound, vibration, etc.) of anincoming call, and replies back with a ‘180 Ringing’ response message94. In the answering stage 78, the terminating side 66 responds with a‘200 OK’ message 96 to the initial ‘Invite’ message 80. In addition, theoriginating side 64 sends an ‘ACK’ message 98 acknowledging that thecall has been answered and that the call is established. With the callestablished, voice (and/or video) data packets go over the dedicatedbearers 72 and 74 via the originating IMS 56 and the terminating IMS 60.

Events related to the call set up process 50 such as the SIP messages,the completion or response times for the SIP messages, and the successor failure at each stage or messaging step may be captured at the server38, allowing the server 38 to generate the CDR 40 for the call set upprocess 50 for both the originating and terminating sides 64 and 66 ofthe initiated call. In other embodiments, a CDR may be generated for theoriginating side 64 or the terminating side 66 only, such as when theparties are subscribed with different networks. The CDR 40 may includeadditional details as well such as, but not limited to, the exact dateand time the call was initiated, the exact time of any call failure, thestage and/or message at which any call failure occurred, the time takento complete or receive a response to each SIP message, the geographicallocation or region of the user device, the type of user device, userdevice software information, user profile, user name, user marketinformation, and user network information. In one embodiment, the server38 is the TAS 42 which may perform additional functions such asin-network answering machine functions and call forwarding.

The specific details of the LTE communication network, the IMS, and thecall set up process described above pertain to an embodiment of VoLTE orViLTE calls. It will be understood that the particular details of thecall set up process may vary on different networks and/or may evolveover time. Furthermore, it will be understood that the structure andoperation of the network and the call set up process may vary for othertypes of communication networks and call sessions.

FIG. 3 shows a method for determining a call set up failure rate on thecommunication network 16 as performed by the server 38, and foradjusting parameters of the communication network 16 based on the callset up failure rate. As used herein, the call set up failure rate is ameasure of the amount of initiated calls on the communication network 16that failed during the call set up process 50 prior to ringing at thecalled party user device 54. That is, the call set up failure rate is ameasure of the amount of initiated calls that failed during the attemptor pre-alerting stages 68 and 70 of the call set up process 50, prior tothe alerting/ringing stage 76. The call set up failure rate is distinctfrom a call drop failure rate which is a measure of the amount ofconnected calls that failed after answering during the progress of thecall between the parties.

At a first block 100, the server 38 may generate a CDR 40 for the callset up process 50 for each call initiated on the communication network16. That is, the server 38 may generate a CDR for each call for which an‘Invite’ message 80 is received at the server 38. If both parties aresubscribed with the same network (e.g., if both or all parties aresubscribers to T-Mobile), then a CDR 40 may be generated for both of theoriginating and terminating sides 64 and 66. In the case of a conferencecall, a CDR may be generated for each leg of the call if, for example,all parties are subscribed to the same network.

At a next block 102, the server 38 may aggregate or combine the CDRs 40generated over a predetermined time period to provide an aggregated CDR.The predetermined time period may be one day, or another preselectedtime period. In some embodiments, the CDRs 40 of a specific market ofinterest may be selected and combined to generate an aggregated CDR thatprovides market specific information regarding call set up failures. Thespecific market of interest may include, for example, a selectedgeographical region, selected types of devices, or a particular network(e.g., T-Mobile, AT&T, etc.).

At a block 104, the server 38 may extract a total number of initiatedcalls from the aggregated call detail record. The number of initiatedcalls is equivalent to the number of ‘Invite’ messages 80 received atthe server 38. Additionally, the server 38 may extract from theaggregated CDR the total number of initiated calls that failed prior tothe alerting/ringing stage 76 (block 106). In one embodiment, the totalnumber of initiated calls that failed prior to the alerting/ringingstage 76 (or the ‘total number of call failures’) is calculatedaccording to equation (1) below, where the ‘total number of callsanswered’ is the number of initiated calls that reached the answeringstage 78, and the ‘total number of calls aborted by a calling party’ isthe number of initiated calls that were aborted by a calling party priorto the alerting/ringing stage 76. For example, the calling party mayhang up and abort the call prior to ringing/notification at the calledparty's device if the calling party dialed the wrong number or wasinterrupted. Equation (1) effectively removes as call set up failuresany calls that successfully reached the answering stage 78, calls thatsuccessfully reached the alerting/ringing stage 76, and calls that wereaborted by the calling party prior to ringing. Additionally, circuitswitched fall backs (CSFBs) are not counted as call set up failures.

Total number of call failures=total number of initiated calls−(totalnumber of calls answered+total number of calls that reached thealerting/ringing stage+total number of calls aborted by the callingparty prior to the alerting/ringing stage)  (1)

Alternatively, the server 38 may analyze the entries in the aggregatedCDR to tally the total number of calls that failed in either the attemptor pre-alerting stages 68 and 70 of the call set up process 50. At anext block 108, the server 38 may calculate the call set up failure ratefrom the total number of initiated calls and the total number of callfailures according to equation (2) below.

Call set up failure rate=total number of call failures/total number ofinitiated calls  (2)

The server 38 may include the call set up failure rate in the aggregatedCDR for analysis by network personnel or engineers. The server 38 mayinclude additional details in the aggregated CDR such as the call set upprocess stages or specific messages in which failures are occurring morefrequently, and/or the reasons for call set up failures at each stage ormessage. This may enable the network to target the stages/messagesexperiencing more failures for optimization.

At a block 110, the server 38 may determine whether the call set upfailure rate is above a threshold indicating that the communicationnetwork 16 is experiencing higher than normal or desired call set upfailures. The threshold may be set according to the preferences of thecommunication network 16. If the call set up failure rate is below thethreshold, the server 38 may continue to generate and aggregate CDRs todetermine the call set up failure rates over the following time periods.If the call set up failure rate is above the threshold, the server 38may trigger an automatic indication or alert to a network computer 114indicating that network servicing may be needed due to high call set upfailures (block 112; also see FIG. 1).

The network computer 114 may receive the indication at a block 116. Inresponse, network personnel or engineers may suitably adjust or optimizeone or more parameters of the communication network 16 to reduce thecall set up failure rate via the network computer 114 or anothercomputer system (block 118). As a non-limiting example, if it isdetermined based on analysis of the aggregated CDR that call set upfailures are occurring more frequently at the ‘183 Session in Progress’messages 84, time limits set on a network timer for receipt of the ‘183Session in Progress’ message 84 may be extended to provide theterminating side 66 with increased time to respond and prevent call setup failures at this messaging step. As another example, networkadjustments may be made to improve signaling and response times duringuser traveling.

Alternatively, the network 16 may decide if network adjustments areneeded based directly on details from the aggregated CDR without anindication or alert. For instance, in one embodiment, network personnelor engineers may receive the aggregated CDR at the network computer 114,and analyze the call set up failure rate and determine whether or notthe rate is higher than desired, and if adjustment of network parameterswould be beneficial to improve subscriber call experience.

Turning to FIG. 4, a portion of an exemplary aggregated CDR 120 isshown. If collected over a time period of one day, the aggregated CDR120 may provide the date on which the calls occurred. The aggregated CDR120 may also list the time of each initiated call (or the time that the‘Invite’ messages were received at the server 38), identifyinginformation describing the cell location from which the call wasinitiated, and details about the originating user device 52 and theterminating user device 54. The status of each initiated call may beprovided such as whether or not the call was answered by the calledparty, whether or not the call was aborted by the calling party duringthe call set up process 50, whether or not the call failed during thecall set up process 50, and the stage and/or message state at which theinitiated call failed if a failure occurred. In the exemplary aggregatedCDR 120, only entries 122 and 124 which experienced a failure prior tothe alerting/ringing stage 76 may be counted as call set up failures.Entries 126 and 128 are not counted as call set up failures because thecalls reached the answering stage 78. Entry 130 is not counted as afailure because the calling party aborted (hung up) prior to ringing atthe called party's device 54, nor is entry 132 because the call reachedthe alerting/ringing stage 76 but was not answered by the called party.

Additional details, such as those described in the preceding paragraphs,may also be included in the aggregated CDR 120 but are not shown herefor clarity purposes. The aggregated CDR 120 of FIG. 4 is exemplary, andmay include other or additional details or have a different appearancein other embodiments.

Certain components of the server 38 that generates the aggregated CDRsand calculates the call set up failure rates is shown in FIG. 5. In oneembodiment, the server 38 is the TAS 42 on the IMS 24 as explainedabove. The server 38 may include a processor 150 physically configuredaccording to computer-executable instructions for performing the variousfunctions described above. For instance, the processor 150 may include aCDR Generator/Aggregator 152 involved in performing functions such asgenerating the CDRs 40 for the initiated calls, and aggregating the CDRsover the predetermined time period. The processor 150 may also have aCDR Analyst 154 which analyzes the aggregated CDR by extracting thetotal call failures and calculating the call set up failure rate. Theserver 38 may also include a memory 156 for storing thecomputer-executable instructions used by the processor 150, as well asother data such as the CDRs and the aggregated CDRs. A communicationcircuit 158 of the server 38 may be in communication with other nodes ofthe communication network 16 such as the CSCF 36 and the networkcomputer 114. The communication circuit 158 may assist in outputting theaggregated CDR, the call set up failure rate, and/or an indication/alertwhen the call set up failure rate is above a threshold to the networkcomputer 114. In other embodiments, another computer system, node, orprogram associated with the communication network 16 may perform orassist in the CDR aggregation, analysis of the aggregated CDR to providethe call set up failure rate, and/or triggering of indications/alerts tothe network computer 114.

The present disclosure provides a solution for adjusting networkparameters based on a metric for the calls that fail during call set upprior to ringing on a given LTE communication network. The call set upfailure rate may be used as a basis for the communication network todecide when adjustments of network parameters are needed to improvesubscriber experience. The metric may also provide a basis for thenetwork to determine if any adjustments made were successful in reducingcall set up failures or in targeting specific stages/messages thatexperience more call set up failures. An alert or indication may betriggered on the network when the call set up failure rate is above athreshold, notifying network personnel or engineers that adjustments ofthe network may be needed to reduce the amount of calls that fail priorto ringing. Furthermore, the call set up failure rate may be determinedfor a selected market on the network, providing information as to whichmarkets (e.g., geographical regions, device types, etc.) may beexperiencing more issues during call set up. In other embodiments, thecall set up failure rates measured on different networks may be used tocompare the performance of different network providers (T-Mobile, AT&T,etc.).

What is claimed is:
 1. A computer-implemented method for adjustingnetwork call parameters based on determining a call set up failure ratefor calls initiated on a long-term evolution (LTE) communicationnetwork, comprising: generating, by a server, at least one call detailrecord for each of the calls initiated on the LTE communication network;aggregating, by the server, the call detail records generated over apredetermined time period to provide an aggregated call detail record;calculating, by the server, the call set up failure rate for the callsfrom the aggregated call detail record; adjusting, by the server, one ormore parameters of the LTE communication network when the call set upfailure rate is above a threshold to reduce the call set up failurerate; and wherein a call set up process for the initiated calls includesan attempt stage, a pre-alerting stage, and an alerting/ringing stage,and wherein the call set up failure rate is a measure of the initiatedcalls that failed during the attempt and pre-alerting stages of the callset up process.
 2. The computer-implemented method of claim 1, whereinthe call set up failure rate excludes the initiated calls that endedafter the pre-alerting stage of the call set up process.
 3. Thecomputer-implemented method of claim 1, wherein the call set up failurerate is calculated according to:call set up failure rate=total number of call failures or total numberof calls initiated on the LTE communication network.
 4. Thecomputer-implemented method of claim 3, wherein the total number of callfailures is calculated according to:total number of call failures=total number of calls initiated on the LTEcommunication network−(total number of calls answered+total number ofcalls that reached the alerting/ringing stage+total number of callsaborted by a calling party prior to the alerting/ringing stage).
 5. Thecomputer-implemented method of claim 1, wherein the predetermined timeperiod is one day.
 6. The computer-implemented method of claim 1,wherein the call set up failure rate is determined for a selected marketof subscribers in the LTE communication network.
 7. Thecomputer-implemented method of claim 1, wherein each of the callsincludes an originating side and a terminating side, and wherein a calldetail record is generated for both of the originating side and theterminating side.
 8. The computer-implemented method of claim 1, whereinthe calls are voice over long-term evolution (VoLTE) calls.
 9. A system,comprising: a communication network configured to enable calls on userdevices subscribed with the communication network, the communicationnetwork at least including a server having a processor, a memory, and acommunication circuit, wherein the communication network comprises along-term evolution (LTE) communication network, the processor beingphysically configured according to computer-executable instructions for:generating a call detail record for a call set up process for each ofthe calls initiated by the user devices; aggregating the call detailrecords generated over a predetermined time period to provide anaggregated call detail record; calculating from the aggregated calldetail record a call set up failure rate for the initiated calls thatfailed during the call set up process; communicating an alert to anetwork computer when the call set up failure rate is above a threshold;and wherein the call set up process includes an attempt stage, apre-alerting stage, an alerting/ringing stage, and an answering stage,and wherein the call set up failure rate excludes the calls that failedduring the alerting/ringing and answering stages of the call set upprocess.
 10. The system of claim 9, wherein the calls include one orboth of voice over long-term evolution (VoLTE) calls and video overlong-term evolution (ViLTE) calls.
 11. The system of claim 9, whereinthe server is a telephony application server (TAS) associated with an IPMultimedia Subsystem (IMS) of the LTE communication network.
 12. Thesystem of claim 9, wherein the LTE communication network is a 4G LTEnetwork or a 5G LTE network.
 13. The system of claim 9, wherein the callset up failure rate is calculated according to:call set up failure rate=total number of call failures or total numberof calls initiated on the LTE communication network.
 14. The system ofclaim 13, wherein the total number of call failures is calculatedaccording to:total number of call failures=total number of calls initiated on the LTEcommunication network−(total number of calls answered+total number ofcalls that reached the alerting/ringing stage+total number of callsaborted by a calling party prior to the alerting/ringing stage).
 15. Thesystem of claim 13, wherein each of the initiated calls includes anoriginating side and a terminating side, and wherein a call detailrecord is generated for one or both of the originating side and theterminating side.
 16. The system of claim 13, wherein the predeterminedtime period is one day.
 17. A computer-implemented method for adjustingnetwork call parameters based on determining a call set up failure ratefor calls initiated on a long-term evolution (LTE) network, comprising:generating, at a server of the LTE communication network, at least onecall detail record for a call set up process for each of the callsinitiated on the LTE communication network; aggregating, at the server,all of the call detail records generated over a predetermined timeperiod to provide an aggregated call detail record; extracting, at theserver, a total number of the initiated calls that failed prior to aringing stage of the call set up process from the aggregated call detailrecord; calculating, at the server, the call set up failure rate basedon the total number of initiated calls that failed prior to the ringingstage; adjusting, at the server, one or more parameters of the LTEnetwork when the call set up failure rate is above a threshold; andwherein a call set up process for the initiated calls includes anattempt stage, a pre-alerting stage, and an alerting/ringing stage, andwherein the call set up failure rate is a measure of the initiated callsthat failed during the attempt and pre-alerting stages of the call setup process.
 18. The computer-implemented method of claim 17, wherein:the call set up failure rate is calculated according to:call set up failure rate=total number of call failures or total numberof calls initiated on the LTE communication network, and the totalnumber of call failures is calculated according to:total number of call failures=total number of calls initiated on the LTEcommunication network−(total number of calls answered+total number ofcalls that reached the ringing stage+total number of calls aborted by acalling party prior to the ringing stage).
 19. The computer-implementedmethod of claim 17, wherein the server is a telephony application server(TAS) associated with an IP Multimedia Subsystem (IMS) of the LTEnetwork.
 20. The computer-implemented method of claim 17, furthercomprising triggering, at the server, an alert to a network computerwhen the call set up failure rate is above the threshold.